[Mika]

Welcome to science; the justification is pretty much always "it happens to work."

I know. Graduated several years ago, publish stuff in the field of Optics - it's a shame they don't mention that often in the classes that dumb luck has a lot to do with scientific progress... Not to discourage those who are still in the University  Also the capability to note that "wait a second, what did it actually do?" or my personal favorite, "it isn't supposed to do that".

The reason I asked about dust is related to the scattering effect with in the plane of the disk and the apparent luminosity around the stars.

More on tomorrow

EDIT: too tired to write coherent English

[Mika]

Okay, back again

I managed to find some of the scattering measurements on galactic level from ADS. In the first article I found, it has been said that the error due to the scattering effect on the galactic luminosity has happened and has been noted.

Thanks for the heads up, now I'll know where to look at next time.

[Astronomiya]

Okay, back again

I managed to find some of the scattering measurements on galactic level from ADS. In the first article I found, it has been said that the error due to the scattering effect on the galactic luminosity has happened and has been noted.

Thanks for the heads up, now I'll know where to look at next time.

Scattering effect?  This would be physical scattering from individual dust particles instead of lensing, right?  If so, that has been known for quite a while I would imagine.  It is after all plainly visible at night when you look at the apparent rifts in the Milky Way, which are all due to dust blocking visible light.